Línekite
A valid IMA mineral species
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About Línekite
Allan Línek
Formula:
K2Ca3[(UO2)(CO3)3]2 · 8H2O
The water content in línekite is somewhat variable and varies between 7 to 8 H2O pfu. The content obtained from crystal-structure studies is everytime underestimated in the case of línekite (see Plášil et al. 2017).
Colour:
Pale olive to khaki green
Lustre:
Vitreous
Hardness:
2 - 3
Specific Gravity:
2.922 (Calculated)
Crystal System:
Orthorhombic
Name:
Línekite is named after Dr. Allan Línek (1925–1984), a Czech physicist and crystallographer of the Institute of Physics, Academy of Sciences of the Czech Republic, for his significant contribution to structure science.
Known synthetically. Chemically close to braunerite.
Línekite forms from uranium-rich aqueous solutions and its origin is associated with post-mining processes.
Línekite forms from uranium-rich aqueous solutions and its origin is associated with post-mining processes.
Name Encoding
ASCII-7:
Linekite
Unique Identifiers
Mindat ID:
43587
Long-form identifier:
mindat:1:1:43587:7
Similar Names
| Lengaite | A synonym of 'Natrocarbonatite' | |
| Lineite | A synonym of Linnaeite | |
| Lun'okite | A valid IMA mineral species | (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2OH · 4H2O |
IMA Classification of Línekite
Approved
IMA Formula:
K2Ca3[(U6+O2)(CO3)3]2(H2O)8
Approval year:
2013
First published:
2017
Classification of Línekite
5.ED.55
5 : CARBONATES (NITRATES)
E : Uranyl Carbonates
D : UO2:CO3 = 1:3
5 : CARBONATES (NITRATES)
E : Uranyl Carbonates
D : UO2:CO3 = 1:3
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Lnk | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Línekite
Vitreous
Transparency:
Transparent
Colour:
Pale olive to khaki green
Streak:
Greenish white to yellowish white
Hardness:
2 - 3 on Mohs scale
Comment:
Estimated
Tenacity:
Brittle
Cleavage:
Perfect
Perfect on {100} and very good cleavage on {010}.
Perfect on {100} and very good cleavage on {010}.
Fracture:
Irregular/Uneven
Density:
2.922 g/cm3 (Calculated)
Optical Data of Línekite
Type:
Biaxial (+)
RI values:
nα = 1.546(2) nβ = 1.550 nγ = 1.562(2)
2V:
Calculated: 60°
Max. Birefringence:
δ = 0.016
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Low (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Chemistry of Línekite
Mindat Formula:
K2Ca3[(UO2)(CO3)3]2 · 8H2O
The water content in línekite is somewhat variable and varies between 7 to 8 H2O pfu. The content obtained from crystal-structure studies is everytime underestimated in the case of línekite (see Plášil et al. 2017).
The water content in línekite is somewhat variable and varies between 7 to 8 H2O pfu. The content obtained from crystal-structure studies is everytime underestimated in the case of línekite (see Plášil et al. 2017).
Element Weights:
Crystallography of Línekite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pnnm
Cell Parameters:
a = 17.0069 Å, b = 18.0273 Å, c = 18.3374 Å
Ratio:
a:b:c = 0.943 : 1 : 1.017
Unit Cell V:
5,622.04 ų (Calculated from Unit Cell)
Morphology:
Tabular, mostly isometric crystals, up to ca. 0.5 mm across: typically in multiple intergrowths.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.506 Å | (100) |
| 6.428 Å | (3) |
| 5.126 Å | (5) |
| 4.586 Å | (2) |
| 4.249 Å | (7) |
| 4.137 Å | (2) |
| 3.543 Å | (2) |
Locality:
Reference:
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47f : [Uranyl (U⁶⁺) minerals] | |
| Stage 10b: Anthropogenic minerals | <10 Ka |
| 55 : Anthropogenic mine minerals |
Type Occurrence of Línekite
General Appearance of Type Material:
Tabular, mostly isometric crystals, up to ca. 0.5 mm across, typically in multiple intergrowths.
Place of Conservation of Type Material:
Department of Mineralogy and Petrology of the National Museum in Prague, Prague, Czech Republic, catalogue number P1P 2/2012
Empirical Formula of Type Material:
(K1.73Na0.02)Σ1.75(Ca2.97Cu0.02)Σ2.99[(UO2)(CO3)3]2.02(H2O)8.00
Chemical Analysis of Type Material:
| Na2O | 0.06 % |
|---|---|
| K2O | 6.89 % |
| CaO | 14.11 % |
| CuO | 0.12 % |
| UO3 | 48.76 % |
| CO2 (calc.) | 22.51 % |
| H2O (calc.) | 12.20 % |
| Total: | 104.65 % |
Geological Setting of Type Material:
Geschieber vein, Svornost mine, Ja´chymov ore district, Western Bohemia, Czech Republic (50º22’21.5’’N 12º54’42.0’’E)
Associated Minerals at Type Locality:
Synonyms of Línekite
Other Language Names for Línekite
Common Associates
Associations Based on Photo Data:
| 11 photos of Línekite associated with Braunerite | K2Ca(UO2)(CO3)3 · 6H2O |
| 5 photos of Línekite associated with Gypsum | CaSO4 · 2H2O |
| 2 photos of Línekite associated with Čejkaite | Na4(UO2)(CO3)3 |
| 2 photos of Línekite associated with Schröckingerite | NaCa3(UO2)(CO3)3(SO4)F · 10H2O |
Related Minerals - Strunz-mindat Grouping
| 5.ED. | Szilagyiite | NaCa3(UO2)(CO3)3(SeO3)F(H2O)6 |
| 5.ED. | Pendevilleite-(Y) | Mg2Y3Al(UO2)2(CO3)7(OH)6(H2O)16 |
| 5.ED. | Paramarkeyite | Ca2(UO2)(CO3)3 · 5H2O |
| 5.ED.05 | Bayleyite | Mg2(UO2)(CO3)3 · 18H2O |
| 5.ED.10 | Swartzite | MgCa(UO2)(CO3)3 · 12H2O |
| 5.ED.15 | Albrechtschraufite | Ca4Mg(UO2)2(CO3)6F2 · 17-18H2O |
| 5.ED.20 | Liebigite | Ca2(UO2)(CO3)3 · 11H2O |
| 5.ED.25 | Rabbittite | Ca3Mg3(UO2)2(CO3)6(OH)4 · 18H2O |
| 5.ED.30 | Andersonite | Na2Ca(UO2)(CO3)3 · 5.33H2O |
| 5.ED.35 | Grimselite | K3Na(UO2)(CO3)3 · H2O |
| 5.ED.40 | Widenmannite | Pb2(OH)2[(UO2)(CO3)2] |
| 5.ED.45 | Znucalite | Zn10Ca0.83(UO2)0.83(CO3)4(OH)15.31(H2O)5.48 |
| 5.ED.50 | Agricolaite | K4(UO2)(CO3)3 |
| 5.ED.50 | Čejkaite | Na4(UO2)(CO3)3 |
| 5.ED.55 | Braunerite | K2Ca(UO2)(CO3)3 · 6H2O |
| 5.ED.60 | Leószilárdite | Na6Mg(UO2)2(CO3)6 · 6H2O |
| 5.ED.65 | Pseudomarkeyite | Ca8(UO2)4(CO3)12 · 21H2O |
| 5.ED.65 | Natromarkeyite | Na2Ca8(UO2)4(CO3)13 · 27H2O |
| 5.ED.65 | Markeyite | Ca9(UO2)4(CO3)13 · 28H2O |
| 5.ED.70 | Paddlewheelite | MgCa5Cu2(UO2)4(CO3)12(H2O)33 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 38.3095% | 9,577,375 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 6.2927% | 1,951 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Fluorescence of Línekite
Intense greenish yellow luminescence under both short- (254 nm) and long-wave (366 nm) UV radiation
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Línekite
mindat.org URL:
https://www.mindat.org/min-43587.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Línekite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) IMA Commission on New Minerals, Nomenclature and Classification. CNMNC Newsletter No. 15. Mineralogical Magazine, 77 (1) 1-12 doi:10.1180/minmag.2013.077.1.01
Localities for Línekite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Czech Republic (TL) | |
| Williams et al. (2013) +1 other reference |
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Svornost Mine, Jáchymov, Karlovy Vary District, Karlovy Vary Region, Czech Republic